The first and simplest IVTs were rolling contact, friction driven; they were followed by belt driven variable pulleys. Millions of great variety of such transmissions are now in use. Their limitations are low efficiency, and inability to handle higher torques. This invention hopes to provide solutions in both these areas.
FIGS. 9(a)-9(d) illustrate how driving forces are now transmitted: FIG. 9(a) shows a most common force transfer—friction, thru a point contact—with the force between the drive/driver parts determined by the set distance between their shafts; FIG. 9(h) shows pulley to a convex surface—again friction thru a point contact; FIG. 9(c) is Nissan's toroidal—two contact points are used, but still using only preset force friction point’ contact; FIG. 9(d) illustrates a typical variable v belt mechanism—a highly inefficient friction transfer. A Dutch made variant of the version shown in FIG. 9(d) has made it into automotive use, and for while a small Ford model many years ago also attempted to adapt such a transmission; all such tries failed.
Automotive transmissions are now as a rule not variable, using step (gear) changes, and can be quite bulky and expensive. Many varieties of “continuously variable” transmissions exist in design only, and more recently a number of infinitely variable ones utilizing a ratcheting function have also appeared.